Hollow metal plumbing structure



Oct. 16, 1962 G. v. MACK ETAL HOLLOW METAL PLUMBING STRUCTURE 5 Sheets-Sheet 1 Filed Sept. 5, 1957 ACK w m m m Oct. 16, 1962 G. V. MACK ET AL Filed Sept. 5, 1957 HOLLOW METAL PLUMBING STRUCTURE 5 Sheets-Sheet 2 IIlIIlllIIIlIlIIIII/n 2e Fl6.4-

INVENTORS RICHARD E. GERHARDT BY GRANT V. MACK Oct. 16, 1962 G. v. MACK ET AL 3,058,203

HOLLOW METAL PLUMBING STRUCTURE Filed Sept. 5, 1957 5 Sheets-Sheet 3 INVENTORS RICHARD E.GERHARDT By GRANT V. MACK ZzZLAX Oct. 16, 1962 G. v. MACK ET AL 3,053,203

HOLLOW METAL PLUMBING STRUCTURE Filed Sept. 5, 1957 5 Sheets-Sheet 4 v INVENTORS RICHARD E. GERHARDT BY GRANT V. MACK Oct. 16, 1962 G. v. MACK ETAL 3,058,203v

HOLLOW METAL PLUMBING STRUCTURE Filed Sept. 5, 1957 5 Sheets-Sheet 5 INVENTORS R\CHARD E. GERHARDT BY GRANT V. MACK Haired States free 3,h53,2ii3 HGLLOW METAL PLEJll iBiNG STRUCTURE Grant V. Mach, Vailey Station, Ky., and Richard E. Gerhardt, .leifersonviiie, ind, assignors to Reynolds Metals Company, Richmond, Va, a corporation of Delaware Filed Sept. 5, 1957, Ser. No, 682,214 2 Claims. Il. 2917) This invention relates to a new method for the production of hollow metal structures having a plurality of interconnecting passageways and internal portions of varying lengths and diameters, in the form of a single sheet of metal, and to the resulting article of manufacture. More particularly, the invention relates to apparatus requiring a funnel with a discharge conduit positioned to discharge into the funnel of such apparatus. Specifically, the invention relates to a unitary metal plumbing system, to the method of manufacture thereof, and to laundry apparatus or washing machines including such unitary metal plumbing systems.

In automatic machines for washing clothes and similar items, and particularly in such machines comprising a combination washer and dryer, the operating elements are customarily included within a cabinet structure. The machines are so constructed that when a load of items which is to be washed, such as soiled clothes, is placed within them, a washing sequence or cycle and then a drying sequence is provided. In the conventional horizontal axis type of machine, a clothes basket or drum is mounted for rotation on a generally horizontal axis within an outer enclosing tub structure. During the operation of the machine the basket is continuously rotated by a flexible belt driven by an electric motor, at predetermined speeds related to the washing or drying cycle. To Warm the wash water during the washing portion of the cycle and also in order to heat the clothes during the drying portion of the cycle, heating elements of the sheathed type are usually provided, in which a resistance wire is maintained in spaced relation to the outer sheath by suitable insulating material, such as those sold commercially, for example, under the trademark Calrod. When these heaters are electrically energized during the Washing cycle, they heat the water either directly or by conduction through the basket dipping into wash water in the lower portion of the tub. During the drying cycle, the heaters supply heat to the clothes, for example, by heat transfer to the basket, to cause water vapor to be driven out of the clothes. This water vapor is subsequently condensed and removed.

The means whereby water is admitted and discharged from the washing tub during operation of the machine, and the control mechanism therefor, conventionally include a pair of connections through which hot and cold water are supplied to the machine. In one well known form of water control device, the water supply means includes a main inlet valve controlled by a solenoid which controls the entry of water during the wash and rinse portions of the wash cycle. An additional valve may be placed in series on the cold water side of the main valve, to serve as the condenser valve and to provide a measured flow of cold water during the drying cycle in order to condense and carry away the moisture removed from the clothes during the heating portion of the drying cycle.

In the water control arrangements of washing and laundry machines presently in use, the plumbing systems which carry the water from the discharge openings of the aforementioned valves to the Washing and drying operations and thence to the drain systems of a solids trap and discharge pump, comprise a complicated arrangement of numerous separate parts, including funnels, rubher and metal tubing, and a vent trap. These many parts are customarily mounted individually on the upper portion of the cabinet structure, adjacent the basket and tub. They require much space, thereby militating against a desirable degree of compactness and accessibility. To accommodate plumbing codes which require an air break in'the drain system, breaks or air gaps must be provided between the inlet water conduits and their corresponding line receiving funnels, so as to make it impossible for water to be siphoned from the machine to contaminate the incoming water supply line. The vibration of the machine frequently causes the water conduits feeding the tunnels to become loosened from their fastenings and to get out of alignment with the funnels, causing leakage and improper operation. The tubing may become rotted or corroded and require replacement.

In accordance with the present invention, there is provided as a single article of manufacture a complete plumbing system for installation between hot or cold water supply connections and the drain system of a laundry or washing machine, which incorporates into a unitary metal structure all the heretofore scattered or separate conduits, funnels, vent units, and other requisite parts. The novel plumbing system of this invention results in a marked saving in space and weight. The various functioning portions of the system are permanently maintained in their proper positions and relationship. The problems of leakage, multiple tastenings, effects of vibration, and the like are entirely overcome. The single unit plumbing system of this invention is simple to install or remove and requires only infrequent replacement, if any at all.

The novel plumbing system comprises as an article of manufacture a homogeneous metal sheet structure including therein a predetermined pattern of conduits, passageways, funnels, inlet and discharge openings, and any other desired portions, in the form of cavities within said sheet structure, and corresponding bulges on one or both outer surfaces of the sheet. The metal employed may be any metal which is adapted to be pressure welded, as tor example, aluminum, or copper, or it may even be a plastic.

In its broader aspects, however, the present invention also concerns a novel method of manufacturing not only the unitary plumbing system including the funnel-discharge conduit system hereinbefore described, but a method which is generally applicable to the production of hollow metal structures having a plurality of interconnected passageways of varying lengths and diameters, for the production of which no effective process has heretofore been available. Briefly, the new method includes the steps of interposing a foreshortened pattern of stopweld material embodying the requisite design including passageways or" varying width, between two sheets of metal to form a composite, fastening the sheets together to prevent slippage and preserve the integrity of the pattern, welding the sheets into a single assembly by a hot rolling operation, forming an opening in a nonbonded portion of the assembly to provide a connection for the introduction of an expansion fluid, placing the assembly in a mold for a first molding stage under a fairly high pressure sufiicient to break loose the unbonded portions corresponding to the original stopweld pattern uniformly throughout the composite sheet, and then in a second molding stage, further expanding the wider unbonded portions of the assembly to the desired dimensions by the use of a lower pressure than in the first stage, said lower pressure being insuflicient substantially to expand further the narrow unbonded portions of the assembly. By means of the various method details and types of molds to be described more fully below, there can be produced in a single tube sheet type of assembly an interconnected and suitably positioned array of separate parts adapted to function together, and in which the various portions provide a diversity of sizes and shapes.

For a better understanding of the invention and its purposes, advantages, and details, reference is now made to the present preferred embodiment of the invention which is shown, for purposes of illustration only, in the accompanying drawings. In the drawings:

FIG. 1 is a perspective view of a pair of metal sheets,

prior to welding, the lower sheet carrying the foreshortened plumbing system pattern;

FIG. 2 is a perspective view of the metal sheet assembly after rolling, the stopweld pattern being indicated in outline;

FIG. 3 is a perspective view of the metal structure showing the passageways in relief following the first expansion step;

FIG. 4 is a sectional view of the metal structure of FIG. 3, taken along the line 44, showing the object within the expansion mold;

FIG. 5 is a perspective view of the metal structure showing the passageways and funnels following the second expansion step;

FIG. 6 is a sectional view of the metal structure of FIG. 5, taken along the line 66, showing the structure supported within the expansion mold;

FIG. 7 is a perspective view of the finished plumbing structure in which superfluous metal portions have been removed;

FIG. 8 is a perspective view of the discharge opening of the system, corresponding generally to line 88 of FIG. 7;

FIG. 9 is a schematic representation of a washing machine basket and tub, showing the unitary plumbing system in relation thereto.

Referring first to FIGS. 1 to 8 inclusive, the method of manufacture of the unitary plumbing system will now be described Two sheets of equal dimensions are prepared, of suitable pressure-weldable metal, as for example, aluminum, copper, and the like, designated, respectively, 10 and 12 in FIG. 1. The method will be illustrated with respect to aluminum sheet, but it will be understood that similar procedures may be applied to other suitable materials.

For fabrication purposes one may advantageously utilize a high grade 99% minimum aluminum sheet, as fabricated, such as, for example, Type 1100-F (former designation 2SF) The surfaces of the two sheets are first thoroughly cleaned in order to assure good bonding in the subsequent hot rolling operation.

A design or pattern of stopweld or separation material 14 is applied to one surface of the lower sheet 12, embodying the various desired parts of the finished plumbing unit. form, in order to allow for elongation of the metal sheets during subsequent rolling. Pattern or bonding portions such as those shown generally at 16, which run in the direction of rolling, will be accordingly increased in length. The pattern of the separation or stopweld material includes such elements of the assembly as conduits, funnels, vent system, and openings for inlet and discharge of water, as depicted at 16 in FIGS. 1 and 2.

The stopweld material may be composed of suitable mixtures of graphite and sodium silicate, with or without the addition of suitable suspending agents, or other equivalent mixtures. The pattern may be applied by stenciling, silk screen process, spraying through a masking die, or by other known methods. The design will generally be in a comparatively thin layer, which should be sufficent to insure bonding of the upper and lower metal sheets at all points except those forming the plumbing elements, and to preventing separation or peeling of the bonded metal sheets after rolling.

Following application of the pattern of stopweld ma- The pattern is applied in foreshortened terial to lower sheet 12, upper sheet 10 is placed upon sheet 12 with the separation material interposed between the two sheets to form a composite as indicated by arrows in FIG. 1. In order to prevent relative motion during the rolling step the sheets are secured to each other by any suitable means, such as edge crimping, welding or sealing, clamping, and the like.

The composite of the two metal sheets and interposed stopweld pattern is then hot rolled in one pass to a suitable thickness, to assume the general outlines shown for composite 18 in FIG. 2. Where, for example, two sheets of aluminum, each 0.125 inch thick are used, forming a composite of approximately 0.250 inch in thickness, the rolling may be performed at a temperature of about 700 F. to provide a bond at the metal interfaces. The rolling may, for example, result in a reduction to a finished gage of about 0.060 inch for the welded composite. This thickness gives generally good results, although gages from 0.050 to 0.070 inch may also be used. Ordinarily with aluminum sheet, the entire reduction can be carried out by hot rolling, and additional cold rolling or annealing treatments are not required. These operations are well known and form no part of the present invention.

In applying the original stopweld pattern to the lower metal sheet 12, provision is made for one portion 20 to extend to the edge of the composite sheet as shown at 22 in FIG. 3. An opening may then be made at entry point 22 and a metal tube applied thereto by any suitable means to provide entry for expansion fluid in the subsequent molding steps.

For the first molding stage, the assembly is placed in a die as shown in'FIG. 4, the inner portions of said die comprising two opposing hollow portions 24 having flat inner surfaces which limit the expansion of the unbonded portions of the assembly. The sheet is firmly gripped by the mold at its outer edges 30. An expansion fluid is applied to the assembly at entry point 22, using a high initial pressure of about 2800-3000 pounds per square inch. This pressure serves to break loose or force apart the unbonded portions corresponding to the original pattern, uniformly throughout the interior of the composite sheet. By causing the various passagesways to form, subject to the restraining inner flat surfaces of the upper and lower halves of the mold, a slightly flattened outer configuration 28 is imparted to the bulged portions on either side of the assembly, as shown in FIGS. 3 and 4. At the completion of this stage, all passageways are of equal depth, although of varying width, as may be seen in FIG. 3. The narrower or uniform width passageways are now fully formed.

The completion of the expansion of the wider passageways within the assembly is performed in a second molding stage, by applying an expansion fluid at a considerably lower pressure. This pressure, which is so regulated that it will produce little or no further expanding or distending effect on the already formed narrower or uniform passageways, is likewise selected so as to expand or distend the wider portions to the full conical or cylindrical shape which they are to assume in the finished device. The pressure required to accomplish this objective may be in the range of 400 to 500 pounds per square inch, but will de pend upon the gage and hardness of the metal, the comparative size and shape of the internal passageways desired, and other obvious factors.

In performing the second stage molding, it has been found that the operation may be carried out in either of two ways. The partly expanded assembly from the first molding stage may be placed in a mold 32 similar to that used in the first stage, but having the interior opposing faces spaced apart a distance corresponding to the maximum diameter of the wider conical or cylindrical portions desired in the finished unit. The partly expanded assembly is placed Within this mold with the outer edges 30 gripped by the mold halves, but otherwise the central por= tions of the assembly are unsupported and subject to free expansion. In one form of the invention, the mold may comprise two flat metal blocks 34 placed in opposing relationship, with the outer edges of the sheet metal assembly gripped by pairs of metal or plastic blocks 36 to hold the assembly firmly in place during expansion. In a second method of molding, some passageway portions of the assembly within the mold may be supported upon pads or blocks 38 of rubber or other resilient material as shown in FIG. 6, to selectively serve to resist unwanted further expansion of these portions.

When the second molding stage has been completed, the assembly will have the fully expanded aspect shown in FIG. 5.

The most important aspect of the invention is the funnel combined with a conduit arranged so as to discharge thereinto which is formed into an integral member from two sheets of starting material.

In order to prepare the finished plumbing assembly, and to provide the air gaps between the conduit passages and their corresponding line funnels, portions of the assembly are cut out or removed by any suitable means, as shown at 40 in FIG. 7. Other superfluous metal portions, shown generally by dotted line 42, may Mso be removed.

The finished assembly 68 as shown in FIG. 7, includes in a single piece, main valve inlet conduit 44, and its corresponding funnel 46, condenser valve conduit 48 and its corresponding funnel 50, vent unit 52 and vent opening 54, and discharge opening 56, which may be beveled as shown in FIG. 8, and is ready for mounting.

The plumbing unit assembly 68 may be readily combined with a washing or laundry machine as shown generally in FIG. 9 by mounting on the cabinet wall thereof, by any suitable means. The inlet conduit 44 is coupled to main valve 58, while the condenser water inlet conduit is coupled to condenser valve 60, in the form of apparatus shown in FIG. 9. The discharge end 62 of funnel 46 is connected to a solids trap 64 which catches foreign particles, the trap in turn being connected to the pump, The opening 54 of the vent trap is connected to an exhaust pipe 66 in the customary manner. In operation, the unitary plumbing assembly performs all the functions heretofore provided by a multiplicity of separate parts.

While the invention has been illustrated by the production of a washing machine plumbing assembly, it will be apparent that the novel method of manufacture herein disclosed may be used generally to fabricate hollow metal structures having a plurality of interconnected passageways of varying widths and diameters, and that the invention may be otherwise variously embodied and practiced within the scope of the following claims.

We claim:

1. Method for the production of a unitary hollow sheet aluminum plumbing system for laundry and washing machines, said plumbing system comprising a plurality of interconnected passageways and internal portions of varying lengths and diameters, and including funnels, a vent unit and a series of connecting conduits as an integral part thereof, which comprises interposing a foreshortened pattern of stopweld material between two sheets of aluminum metal containing not less than 99% aluminum, said sheets having a thickness of about 0.125 inch each, said pattern defining funnel, vent unit, and conduit portions which will not be bonded upon subsequent pressure welding, pressure welding said sheets together by a hot rolling operation, forming an opening in a nonbonded portion of the assembly to provide a connection for the introduction of an expansion fluid, introducing an expansion fluid at a pressure of about 2800 to 3000 pounds per square inch in a first molding stage to loosen and separate the unbonded portions to an extent defined by a pair of opposing flat surfaces equidistant from the center of the assembly, thereby forming conduit portions of uniform diameter, then in a second molding stage introducing an expansion fluid at a pressure of about 400 to 500 pounds per square inch to expand further to the desired dimensions the vent unit and funnel portions, said second molding stage being carried out in a mold comprising a pair of opposing flat surfaces equidistant from the center of the assembly and spaced a greater distance apart than the pair of opposing fiat surfaces in the first molding stage, said assembly being supported at its edges between said sufaces, the central portions of the assembly being unsupported and subject to free expansion so that a flattened surface is formed at the exterior of said vent unit and funnel portions, and removing portions of the aluminum to define the edges of the funnels and of the outer openings of the conduits.

2. Method for the production of a unitary hollow sheet metal plumbing system for laundry and washing machines, said plumbing system comprising a plurality of interconnected passageways and internal portions of varying lengths and diameters, and including funnel-s, a vent unit, and a series of connecting conduits as an integral part thereof, which comprises interposing a foreshortened pattern of stopweld material between two sheets: of pressure-weldable metal selected from the group consisting of aluminum and copper, said pattern defining funnel, vent unit, and conduit portions which will not be bonded upon subsequent pressure welding, pressure welding said sheets together by a hot rolling operation, forming an opening in a nonbonded portion of the assembly to provide a connection for the introduction of an expansion fluid, introducing an expansion fluid at high pressure in a first molding stage to loosen and separate the unbonded portions to an extent defined by a pair of opposing flat surfaces equidistant from the center of the assembly, thereby forming conduit portions of uniform diameter, then in a second molding stage introducing an expansion fluid at a pressure considerably lower than the pressure of the first expansion fluid and which is in-suflicient to expand further the said already formed conduit portions, but which will expand further to the desired dimensions the vent unit and funnel portions, said second molding stage being carried [out in a mold comprising a pair of opposing flat surfaces equidistant from the center of the assembly and spaced a greater distance apart than the pair of opposing flat surfaces in the first molding stage, said assembly being supported at its edges between said surfaces, the central portions of the assembly being unsupported and subject to free expansion and the already formed conduit portions being supported between blocks of resilient mate-rial to resist further expansion, and removing portions of the metal to define the edges of the tunnels and of the outer openings of the conduits.

References Cited in the file of this patent UNITED STATES PATENTS 2,110,430 Swanson Mar. 8, 1938 2,250,974 Stoddard July 29, 1941 2,498,275 Johnson Feb. 21, 1950 2,638,1 12 Shelton May 12, 1953 2,662,273 Lon-g Dec. 15, 1953 2,690,002 Grenell Sept. 28, 1954 2,740,188 Simmons Apr. 3, 1956 2,756,487 Heidorn July 31, 1956 2,759,247 Grenell Aug. 21, 1956 2,779,086 Rieppel Jan. 29, 1957 2,779,173 Wurtz Jan. 29, 1957 2,795,113 Wurtz June 11, 1957 2,835,961 Neel May 27, 1958 2,837,810 E-lkhorn June 10, 1958 2,857,659 Staples Oct. 28, 1958 2,892,325 Timrner June 30, 1959 FOREIGN PATENTS 323,428 Italy Dec. 20, 1924 212,262 Australia June 27, 1957 

